Halo Structure and RR Lyrae Stars in the SDSS-II Supernova Survey

密歇根州立大学的霍勒斯·史密斯博士将在斯隆数字巡天II超新星巡天期间反复覆盖的300平方度的天空中识别出天琴座RR星。 光变曲线，金属丰度，并在某些情况下，径向速度将确定这些RR天琴座恒星。这次巡天不仅将揭示天琴座RR型恒星在迄今为止研究非常不完全的天空区域中的整体空间分布，而且还可能识别出与不同合并事件相关的天琴座RR型恒星的子集。 天琴座RR型恒星是一种脉动恒星，其进化的祖先见证了光环的形成，是很好的标准烛光，可以为银河系的形成提供特别的见解。拟议的研究将成为密歇根州立大学天体物理学研究生和本科生培训的重要组成部分。这项研究，连同其他可变星星的研究正在进行的密歇根州立大学，也将提供一个重点吸引天文学家在密歇根州地区的地方会议变星。更广泛的影响将通过描述研究的网页以及通过在校园天文台开放日之夜向公众介绍来实现。中学教师将在校园天文台举行的会议上了解观察和这项研究，教师将能够在那里获得自己的观察结果。

Dr. Horace Smith, at Michigan State University, will identify RR Lyrae stars within the 300 square degree strip of sky that is being repeatedly covered during the Sloan Digital Sky Survey II supernova survey. Light curves, metallicities, and, in some cases, radial velocities will be determined for these RR Lyrae stars. This survey will not only reveal the overall space distribution of RR Lyrae stars in a hitherto very incompletely studied region of the sky, but it is also likely to identify subsets of RR Lyrae stars associated with distinct merger events. RR Lyrae stars, pulsating stars whose evolutionary progenitors were eyewitnesses to the formation of the halo and which are excellent standard candles, can provide particular insight into the building of the Milky Way.The proposed research will form an important part of the training of both graduate and undergraduate astrophysics students at Michigan State University. This research, together with other variable star studies being carried out at MSU, will also provide a focus for drawing astronomers in the Michigan area to local meetings on variable stars. A wider impact will be achieved through a web page describing the research and also through presentations to the public during open house nights at the campus observatory. Secondary school teachers will be introduced to observing and to this research at sessions held at the campus observatory, where the teachers will be able to obtain observations of their own